The objective is to better understand the functioning of the Human Auditory System after it has been exposed to intense sounds. Most previous research on auditory adaptation has concentrated on temporary threshold shift (TTS)--and permanent threshold shift (PTS)--the rise in absolute sensitivity that follows exposure. The research proposed here is more concerned with how the processing of suprathreshold waveforms is altered following exposure. What is the nature and time-course of recovery of temporary loudness shift (TLS) and temporary pitch shift (TPS) and how do they vary as a function of the standard loudness? What is the nature of the exposure-induced recruitment across test frequencies on either side of the exposure frequency? Are the temporal-integration or frequency-resolution characteristics of the system altered for suprathreshold stimuli? A little is known about each of these issues from past research, but there has never been a parametric examination of the various topics using similar psychophysical procedures, exposures, etc. This knowledge is important to have, not just for its own sake, but because it is necessary for the establishment of sensible occupational-health goals and standards. One of the primary psychophysical procedures will be the alternate binaural loudness balance (ABLB), modified slightly depending upon the issue of interest; an adaptive psychophysical procedure will also be employed when possible. The exposure intensities used will all be safe according to the best available evidence, and numerous precautions will be taken to protect the hearing of the subjects. The maximum exposure that will ever be used is 110 dB for 15 minutes, which in a worst-case situation produces about 40 dB of TTS that is completely recovered from in a few hours. The hope is that all subjects will be undergraduate or graduate students in Audiology or Speech Pathology, and we will build upon this base of knowledge by lecturing and assigning readings on adaptation.